 You don't have to be particularly observant to notice the abrupt change in vegetation type from the grassy place where I'm standing to the shrub thicket a few meters away, but you might be interested in why it's that way and what it has to do with life in northern Wyoming. The shrub we're looking at is called Curleaf Mountain Mahogany and it's found in the drier landscapes of northern Wyoming. It has a close relative, the true mountain mahogany, that lives farther south. Both species of mountain mahogany are heavily browsed by deer in the winter and are important part of the diet. The more heavily the shrubs are used by deer, the more spines they produce to protect themselves. Mountain mahogany thrives on shallow, poorly developed soils that are usually high in calcium. It grows almost on bedrock here in the foothills up to about 7,500 feet elevations. One of the advantages mountain mahogany has on these tough sites is that they produce their own supply of nitrogen. So when mountain mahogany stays where it is now, it has a sort of home field advantage. However, when the shrubs venture out onto the deeper soils, they're subjected to strong competition from the grasses for water and nutrients and to more frequent wildfires. Mountain mahogany is just one of the hundreds of tough critters that make Wyoming interesting. From the University of Wyoming Cooperative Extension Service, I'm Zola Ryan.